JP2019182145A - tire - Google Patents

Abstract

To provide a tire capable of continuously exhibiting excellent on-snow performance.SOLUTION: A tire comprises a tread portion 2. The tread portion 2 comprises a land part 10 partitioned by a first edge 10a extending in a tire circumferential direction and a second edge 10b extending in the tire circumferential direction. The land part 10 comprises: first lateral grooves 15 extending from the edge 10a toward the second edge 10b, and terminating within the land part; longitudinal grooves 16 extending in the tire circumferential direction continuing to the first lateral grooves 15, and terminating within the land part; and sipes 17 continuing to the longitudinal grooves 16 and extending to the second edge 10b side.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a tire, and more particularly to a tire suitable for running on snow.

  In the following Patent Document 1, a lug groove having an inner end extending from the main groove and terminating in the land portion and a vertical slot communicating with the lug groove and having both ends terminating in the land portion are provided in the tread portion. Pneumatic tires have been proposed.

JP, 2006-107912, A

  When running on snow with the tire of Patent Document 1, the lug grooves and slots tend to be clogged with snow. And once these clogs and the like are clogged with snow, there is a problem that the on-snow traction using these ditches cannot be obtained and the performance on the snow is lowered.

  The present invention has been devised in view of the above problems, and has as its main object to provide a tire that can continuously exhibit excellent performance on snow.

  The present invention is a tire having a tread portion, the tread portion including a first portion extending in the tire circumferential direction and a land portion divided by a second edge extending in the tire circumferential direction, and the land portion Includes a first lateral groove extending from the first edge toward the second edge and terminating in the land portion, extending in the tire circumferential direction along the first lateral groove, and having both end portions on the land. A longitudinal groove that is interrupted in the part and a sipe that extends to the second edge side in a row with the longitudinal groove are provided.

  In the tire of the present invention, it is preferable that the first lateral groove is inclined with respect to the tire axial direction.

  In the tire according to the aspect of the invention, it is preferable that the first lateral groove includes a portion where the groove width is enlarged toward the longitudinal groove side.

  In the tire of the present invention, it is preferable that the vertical groove has a depth smaller than that of the first horizontal groove.

  In the tire according to the present invention, it is preferable that the sipe extends to the second edge.

  In the tire according to the present invention, it is desirable that the sipe has a depth larger than the longitudinal groove.

  In the tire of the present invention, it is preferable that at least a part of the sipe is located in a region where the first lateral groove is extended in the length direction.

  In the tire of the present invention, it is desirable that the first lateral groove and the sipe are inclined in the same direction with respect to the tire axial direction.

  In the tire of the present invention, the land portion has a chamfered portion including an inclined surface disposed between the tread surface and the side wall on the second edge side, and the sipe extends to the chamfered portion. Is desirable.

  In the tire of the present invention, the tread portion includes another land portion adjacent to the land portion through a main groove disposed on the second edge side of the land portion, and the other land portion includes: It is desirable that a second lateral groove that is continuous with the main groove is provided.

  In the tire according to the aspect of the invention, it is preferable that the sipe is continuous with the main groove, and a region in which the sipe is extended along the length direction intersects with an end portion of the second lateral groove.

  The land portion divided into the tread portion of the tire of the present invention has a first lateral groove extending from the first edge toward the second edge and terminating in the land portion, and a tire circumferential direction connected to the first lateral groove. And a sipe that extends to the second edge side and is connected to the longitudinal groove.

  The first horizontal groove and the vertical groove provide great traction by driving and solidifying the snow inside the snow and shearing it. In particular, at the connection portion between the first horizontal groove and the vertical groove, the snow is more strongly pressed and a large snow column shear force is exhibited. In addition, since the sipe makes the land portion in the vicinity of the longitudinal groove moderately easily deformed, the snow compacted in the first lateral groove and the longitudinal groove is easily discharged by the deformation of the land portion and has excellent on-snow performance. Is sustained.

It is an expanded view of the tread part of the tire of one embodiment of the present invention. It is an enlarged view of the outer middle land part and crown land part of FIG. It is an enlarged view of the 1st horizontal groove of FIG. 2, a vertical groove, and a sipe. (A) is the sectional view on the AA line of FIG. 2, (b) is the sectional view on the BB line of FIG. 2, (c) is the sectional view on the CC line of FIG. . It is an enlarged view of the outer side shoulder land part of FIG. It is an enlarged view of the inner middle land part and inner shoulder land part of FIG. It is an expanded view of the tread part of the tire of other embodiments of the present invention. It is an expanded view of the tread part of the tire of a comparative example.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a development view of the tread portion 2 of the tire 1 of the present embodiment. The tire 1 of the present embodiment is a pneumatic tire for passenger cars, for example, and is preferably used for all seasons that can also support running on snow. However, the tire 1 of the present invention is not limited to such an embodiment.

  As shown in FIG. 1, the tire 1 of the present embodiment includes, for example, a tread portion 2 in which the mounting direction to the vehicle is specified. The tread portion 2 has an outer tread end To positioned on the vehicle outer side when the tire 1 is mounted on the vehicle, and an inner tread end Ti positioned on the vehicle inner side when the vehicle is mounted. The direction of mounting on the vehicle is displayed by, for example, characters or symbols on a sidewall portion (not shown).

  In the case of a pneumatic tire, each tread end To, Ti is a grounding position on the outermost side in the tire axial direction when a regular load is applied to the regular tire 1 and grounded on a plane with a camber angle of 0 °. The normal state is a state in which the tire is assembled on the normal rim and is filled with the normal internal pressure, and further, there is no load. In this specification, when there is no notice in particular, the dimension of each part of a tire, etc. are values measured in the normal state.

  The “regular rim” is a rim determined for each tire in the standard system including the standard on which the tire is based. For example, “Standard Rim” for JATMA, “Design Rim” for TRA, and “ETRTO” If there is "Measuring Rim".

  “Regular internal pressure” is the air pressure that each standard defines for each tire in the standard system including the standard on which the tire is based. “JATMA” is the “highest air pressure”, TRA is the table “TIRE LOAD LIMITS AT” The maximum value described in “VARIOUS COLD INFLATION PRESSURES”, “INFLATION PRESSURE” for ETRTO.

  “Regular load” is a load determined by each standard for each tire in the standard system including the standard on which the tire is based. “JAMATA” is “Maximum load capacity”, TRA is “TIRE LOAD LIMITS” The maximum value described in “AT VARIOUS COLD INFLATION PRESSURES”, “LOAD CAPACITY” in the case of ETRTO.

  The tread portion 2 is provided with a plurality of main grooves extending continuously in the tire circumferential direction. The plurality of main grooves include, for example, an outer shoulder main groove 3, an inner shoulder main groove 4, an outer crown main groove 5, and an inner crown main groove 6. Each of the main grooves 3 to 6 of the present embodiment extends linearly, for example, but is not limited to such a mode, and may be, for example, a zigzag shape.

  The outer shoulder main groove 3 is provided, for example, on the outermost tread end To side among the plurality of main grooves. The inner shoulder main groove 4 is provided, for example, on the innermost tread end Ti side among the plurality of main grooves. The outer crown main groove 5 is provided between the outer shoulder main groove 3 and the tire equator C, for example. The inner crown main groove 6 is provided between the inner shoulder main groove 4 and the tire equator C, for example.

  In the outer shoulder main groove 3 and the inner shoulder main groove 4, for example, the distance L1 from the tire equator C to the groove center line is preferably 0.20 to 0.30 times the tread width TW. In the outer crown main groove 5 and the inner crown main groove 6, for example, the distance L2 from the tire equator C to the groove center line is preferably 0.05 to 0.15 times the tread width TW. The tread width TW is a distance in the tire axial direction from the outer tread end To to the inner tread end Ti in the normal state.

  The groove width W1a of the outer shoulder main groove 3, the groove width W1b of the inner shoulder main groove 4, the groove width W1c of the outer crown main groove 5, and the groove width W1d of the inner crown main groove 6 are, for example, 4 to 7 of the tread width TW. % Is desirable. The groove width W1a of the outer shoulder main groove 3 is, for example, the smallest among the groove widths of the plurality of main grooves. The groove width W1c of the outer crown main groove 5 is smaller than the groove width W1b of the inner shoulder main groove 4, for example. The groove width W1d of the inner crown main groove 6 is, for example, the largest among the groove widths of the plurality of main grooves. Such distribution of the groove width is useful for improving the steering stability on the dry road surface and the performance on snow in a well-balanced manner. Each main groove 3 to 6 desirably has a depth of, for example, about 5 to 10 mm in the case of a tire for a passenger car. However, the dimensions of the main grooves 3 to 6 are not limited to such a range.

  By providing the main grooves 3 to 6 described above, the tread portion 2 is divided into a plurality of land portions. In the tread portion 2 of the present embodiment, an outer shoulder land portion 8, an inner shoulder land portion 9, an outer middle land portion 10, a crown land portion 11, and an inner middle land portion 12 are divided. The outer shoulder land portion 8 is divided between the outer shoulder main groove 3 and the outer tread end To. The inner shoulder land portion 9 is divided between the inner shoulder main groove 4 and the inner tread end Ti. The outer middle land portion 10 is divided between the outer shoulder main groove 3 and the outer crown main groove 5. The crown land portion 11 is divided between the outer crown main groove 5 and the inner crown main groove 6. The inner middle land portion 12 is divided between the inner shoulder main groove 4 and the inner crown main groove 6.

  FIG. 2 shows an enlarged view of the outer middle land portion 10 and the crown land portion 11 as a diagram for explaining an example of the land portion. As shown in FIG. 2, the outer middle land portion 10 is divided between a first edge 10a and a second edge 10b. In the present embodiment, the first edge 10a is an edge that extends in the tire circumferential direction on the outer tread end To side. The second edge 10b is an edge extending in the tire circumferential direction on the tire equator C side.

  The outer middle land portion 10 is provided with a first lateral groove 15, a longitudinal groove 16 and a sipe 17. FIG. 3 shows these enlarged views. As shown in FIG. 3, the first lateral groove 15 extends from the first edge 10a toward the second edge 10b and terminates in the land portion. The vertical groove 16 is continuous with the first horizontal groove 15 and extends in the tire circumferential direction, and both end portions are interrupted in the land portion. The sipe 17 continues to the longitudinal groove 16 and extends toward the second edge 10b. In the present specification, “sipe” means a cut having a width of less than 1.5 mm.

  The first horizontal groove 15 and the vertical groove 16 provide large traction by pressing and hardening the snow inside and shearing it when traveling on snow. In particular, in the connection portion between the first horizontal groove 15 and the vertical groove 16, the snow is more strongly pressed and a large snow column shear force is exhibited. Further, the sipe 17 makes it easy to moderately deform the land portion in the vicinity of the vertical groove, so that the snow compacted in the first horizontal groove 15 and the vertical groove 16 is easily discharged due to the deformation of the land portion. The performance on snow is sustained.

  In the present embodiment, the groove element including the first horizontal groove 15, the vertical groove 16, and the sipe 17 is disposed in the outer middle land portion 10, but the present invention is not limited to such a mode, and the groove element May be placed on any land.

  As shown in FIG. 2, the first horizontal groove 15, the vertical groove 16, and the sipe 17 of the present embodiment are arranged in each of a plurality of blocks 20 divided by a through groove 19 that completely crosses the land portion, for example. Yes.

  The first lateral groove 15 is inclined with respect to the tire axial direction, for example. The angle θ1 of the first lateral groove 15 with respect to the tire axial direction is preferably, for example, 45 ° or less, and specifically 25 to 35 °. Such a first lateral groove 15 can improve not only the snow traction but also the turning performance when traveling on snow.

  It is desirable that the first lateral groove 15 includes, for example, a portion where the groove width increases toward the vertical groove 16 side. In the first horizontal groove 15 of the present embodiment, for example, a widened portion 15b having an enlarged groove width is connected to the vertical groove 16 side of a constant width portion 15a extending from the first edge 10a with a constant groove width. 15 b is connected to the longitudinal groove 16. Such first lateral grooves 15 can further suppress clogging of snow inside.

  The groove width W2 (shown in FIG. 3) of the first lateral groove 15 is, for example, the groove width of the main groove on the first edge 10a side (in this embodiment, the groove width W1a of the outer shoulder main groove 3 shown in FIG. 1). It is desirable to be 0.40 to 0.65 times. Such first lateral grooves 15 can improve the steering stability on the dry road surface and the performance on snow in a well-balanced manner.

  The longitudinal groove extends, for example, at an angle of 20 ° or less, more preferably 10 ° or less with respect to the tire circumferential direction. In the present embodiment, the longitudinal groove extends parallel to the tire circumferential direction. Further, the longitudinal groove 16 extends linearly. However, it is not limited to such an aspect, For example, the vertical groove 16 may extend zigzag.

  The vertical groove 16 preferably has a groove width W3 smaller than that of the first horizontal groove 15, for example. The groove width W3 of the vertical groove 16 is desirably 0.50 times or less of the groove width W2 of the first horizontal groove 15, for example, specifically 0.30 to 0.45 times the groove width W2. Is desirable.

  As shown in FIG. 3, the length L4 of the longitudinal groove 16 in the tire circumferential direction is preferably at least smaller than the length L3 of the block 20 in the tire circumferential direction. For example, the length L4 of the longitudinal groove 16 is preferably less than or equal to half of the length L3, and specifically, is preferably 0.10 to 0.30 times the length L3. Such vertical grooves 16 can exhibit excellent on-snow performance while maintaining steering stability on a dry road surface.

  In the present embodiment, when the longitudinal groove 16 is divided into three groove portions having the same tire circumferential direction length, it is desirable that the first lateral groove 15 is continuous with the central groove portion 16a in the tire circumferential direction. In a more desirable mode, the distance L5 in the tire circumferential direction between the end on the second edge 10b side of the groove center line of the first lateral groove 15 and the center position 16c in the tire circumferential direction of the longitudinal groove 16 is the groove width of the first lateral groove 15. It is desirable to be smaller than W2. The distance L5 is preferably 0.05 to 0.20 times the groove width W2. Thereby, snow can be strongly pressed and hardened by the groove part 16a of the center of the vertical groove 16, and a big snow column shear force is exhibited.

  For example, the sipe 17 preferably extends from the longitudinal groove 16 to the second edge 10b. Such a sipe 17 can further suppress the clogging of snow in the first horizontal groove 15 and the vertical groove 16.

  It is desirable that the sipe 17 is continuous with the central groove portion 16a of the vertical groove 16, for example. Accordingly, at least a part of the sipe 17 is located in a region where the first lateral groove 15 is extended in the length direction. In a further desirable mode, the entire sipe 17 is located within the region. Thereby, the above-described effect can be further enhanced.

  For example, the sipe 17 is preferably inclined in the same direction as the first lateral groove 15 with respect to the tire axial direction. The angle θ2 of the sipe 17 with respect to the tire axial direction is, for example, 25 to 35 °. In the present embodiment, the difference between the angle θ1 of the first lateral groove 15 with respect to the tire axial direction and the angle θ2 of the sipe 17 with respect to the tire axial direction is less than 10 °. Such a sipe 17 makes it easy to open the first horizontal groove 15 and can further suppress the clogging of snow in the first horizontal groove 15 and the vertical groove 16.

  FIG. 3 shows a cross-sectional view of the first horizontal groove 15, the vertical groove 16, and the sipe 17 along the line AA. As shown in FIG. 3, the vertical groove 16 has a depth smaller than that of the first horizontal groove 15, for example. The depth d2 of the vertical groove 16 is, for example, 0.20 to 0.50 times the depth d1 of the first horizontal groove 15. Such a longitudinal groove 16 is useful for improving the steering stability on the dry road surface and the performance on snow in a well-balanced manner.

  The sipe 17 has a depth smaller than that of the first lateral groove 15, for example. The sipe 17 has a depth larger than that of the longitudinal groove 16. Specifically, the depth d3 of the sipe 17 is 0.50 to 0.80 times the depth d1 of the first lateral groove 15, for example.

  As shown in FIG. 2, the outer middle land portion 10 has a chamfered portion 21 including an inclined surface disposed between the tread surface and the side wall on the second edge 10b side. The sipe 17 preferably extends to the chamfered portion 21. When running on snow, the outer crown main groove 5 forms a hard snow column near the chamfered portion 21 and provides a large snow column shear force. Further, the chamfered portion 21 connected to the sipe 17 is easily deformed moderately, and can prevent the main groove from being clogged with snow.

  The through groove 19 provided in the outer middle land portion 10 is inclined in the same direction as the first lateral groove 15 with respect to the tire axial direction, for example. The angle θ3 of the through groove 19 with respect to the tire axial direction is preferably 20 to 35 °, for example.

  The through groove 19 has, for example, a larger groove width than the vertical groove 16. Specifically, the groove width W4 of the through groove 19 is desirably 1.5 to 2.5 times the groove width W3 of the vertical groove 16.

  FIG. 4B shows a cross-sectional view of the through groove 19 along the line BB. As shown in FIG. 4B, the through groove 19 has, for example, a raised portion 23 in which the groove bottom is raised on the first edge 10a side. The depth d5 of the raised portion 23 is, for example, 0.60 to 0.70 times the maximum depth d4 of the through groove 19. Moreover, the width | variety of the tire axial direction of the protruding part 23 is 0.40-0.60 times the width | variety of the tire axial direction of the outer middle land part 10, for example. Such a raised portion 23 can suppress the through-groove 19 from opening excessively, and as a result, can improve steering stability on a dry road surface.

  As shown in FIG. 2, the outer middle land portion 10 is preferably provided with, for example, a through sipe 25 that completely crosses the land portion. For example, in the block 20, one through sipe 25 is provided on one side and the other side of the first lateral groove 15 in the tire circumferential direction. The penetrating sipe 25 can provide a large frictional force when traveling on ice.

  The through sipe 25 is inclined in the same direction as the first lateral groove 15, for example. The angle θ4 of the through sipe 25 with respect to the tire axial direction is preferably 20 to 30 °, for example.

  FIG. 4C shows a cross-sectional view of the through sipe 25 taken along the line CC. As shown in FIG. 4C, the through sipe 25 includes, for example, a first raised portion 26 whose bottom portion is raised on the second edge 10b side, and a second raised portion 27 whose bottom portion is raised on the first edge 10a side. Including. The depth d7 of the first raised portion 26 is, for example, 0.25 to 0.40 times the maximum depth d6 of the penetrating sipe 25. The depth d8 of the second raised portion 27 is, for example, 0.60 to 0.75 times the maximum depth d6 of the penetrating sipe 25. Each raised part can suppress the penetration sipe 25 from opening excessively, and can improve on-snow performance and on-ice performance while maintaining steering stability on a dry road surface.

  For example, the second raised portion 27 desirably has a larger width in the tire axial direction than the first raised portion 26. The width of the second raised portion 27 of the present embodiment in the tire axial direction is the same as the width of the raised portion 23 of the through groove 19. Such penetrating sipe 25 can increase the rigidity of the outer middle land portion 10 on the outer tread end To side together with the penetrating groove 19, and consequently improve the steering stability on the dry road surface.

  As shown in FIG. 2, the tread portion 2 has another land portion adjacent to the outer middle land portion 10 via the outer crown main groove 5 disposed on the second edge 10 b side of the outer middle land portion 10. The crown land portion 11 is divided.

  For example, a second lateral groove 29 is provided in the crown land portion 11. For example, the second lateral groove 29 extends from the outer crown main groove 5 to the outer tread end Te side, and is interrupted in the crown land portion 11. The second lateral groove 29 of the present embodiment is interrupted without crossing the tire equator C, for example.

  For example, the second lateral groove 29 is inclined in the same direction as the first lateral groove 15 with respect to the tire axial direction. For example, the angle θ5 of the second lateral groove 29 with respect to the tire axial direction is preferably larger than the angle θ1 of the first lateral groove 15 with respect to the tire axial direction. Specifically, the angle θ5 is desirably 50 to 70 °. Such second lateral grooves 29 can improve the turning performance when traveling on snow.

  In the present embodiment, it is desirable that the region obtained by extending the sipe 17 along the length direction intersects the end of the second lateral groove 29. In a more desirable mode, the end portion of the second lateral groove 29 intersects with a region in which the chamfered portion 21 of the outer middle land portion 10 extends toward the inside in the tire axial direction. Thereby, a hard snow column can be formed in the vicinity of the second lateral groove 29 and the chamfered portion 21, and the second lateral groove 29 can be prevented from being clogged with snow.

  The crown land portion 11 is provided with a plurality of crown sipes 30. Each crown sipe 30 is inclined in the same direction as the first lateral groove 15, for example. The angle θ6 of the crown sipe 30 is preferably 20 to 30 °, for example.

  The crown sipe 30 includes, for example, a first crown sipe 31, a second crown sipe 32, and a third crown sipe 33. For example, the first crown sipe 31 extends from the end of the second lateral groove 29 to the inner crown main groove 6. For example, the second crown sipe 32 is connected to the second lateral groove 29 on the outer tread end To side of the first crown sipe 31 and extends to the inner crown main groove 6. For example, the third crown sipe 33 completely crosses the crown land portion 11. Such an arrangement of the crown sipes 30 is useful for improving the steering stability on the dry road surface and on-snow performance in a well-balanced manner while suppressing uneven wear on the land.

  The crown land portion 11 is provided with a crown chamfered portion 34 including an inclined surface disposed between the tread surface and the side wall on the inner crown main groove 6 side. The end portion of the third crown sipe 33 on the inner tread end Ti side is preferably connected to the crown chamfered portion 34. Thereby, it becomes difficult for the inner crown main groove 6 to be clogged with snow, and excellent on-snow performance is continuously exhibited.

  FIG. 5 shows an enlarged view of the outer shoulder land portion 8. As shown in FIG. 5, the outer shoulder land portion 8 is provided with, for example, a plurality of first outer shoulder lateral grooves 36 and second outer shoulder lateral grooves 37.

  For example, the first outer shoulder lateral groove 36 extends from the outer tread end To to the outer shoulder main groove 3. The first outer shoulder lateral groove 36 is preferably inclined, for example, in the direction opposite to the first lateral groove 15 with respect to the tire axial direction.

  For example, the second outer shoulder lateral groove 37 extends from the outer tread end To to the tire equator C side, and is interrupted in the outer shoulder land portion 8. Such second outer shoulder lateral grooves 37 can improve the performance on snow while maintaining steering stability on a dry road surface.

  The outer shoulder land portion 8 of the present embodiment is provided with an outer shoulder vertical narrow groove 38, an outer shoulder chamfered portion 39, a first outer shoulder sipe 41, and a second outer shoulder sipe 42.

  The outer shoulder vertical narrow groove 38 communicates, for example, between the first outer shoulder lateral grooves 36 adjacent in the tire circumferential direction. In a desirable mode, the outer shoulder vertical narrow groove 38 passes between the second outer shoulder lateral groove 37 and the outer shoulder main groove 3 and extends linearly in parallel to the tire circumferential direction.

  The outer shoulder chamfered portion 39 includes an inclined surface disposed between the tread surface of the outer shoulder land portion 8 and the side wall on the outer shoulder main groove 3 side. In a desirable mode, it is desirable that a region obtained by extending the outer shoulder chamfered portion 39 in the tire axial direction intersects with the end portion of the first lateral groove 15.

  The first outer shoulder sipe 41 is, for example, disposed between the first outer shoulder lateral groove 36 and the second outer shoulder lateral groove 37 and extends in the tire axial direction. The first outer shoulder sipe 41 extends, for example, from the outer shoulder vertical narrow groove 38 toward the outer tread end To, and is interrupted in front of it.

  For example, the second outer shoulder sipe 42 extends from the end of the second outer shoulder lateral groove 37 to the outer shoulder main groove 3. The second outer shoulder sipe 42 of this embodiment is connected to, for example, the outer shoulder chamfered portion 39.

  FIG. 6 shows an enlarged view of the inner middle land portion 12 and the inner shoulder land portion 9. As shown in FIG. 6, the inner middle land portion 12 is provided with a plurality of first inner middle lateral grooves 43 and second inner middle lateral grooves 44. The first inner middle lateral groove 43 and the second inner middle lateral groove 44 are preferably inclined in the same direction as the first lateral groove 15, for example.

  For example, the first inner middle lateral groove 43 completely crosses the inner middle land portion 12. For example, the second inner middle lateral groove 44 extends from the inner crown main groove 6 toward the inner tread end Ti side, and is interrupted in the inner middle land portion 12.

  The inner middle land portion 12 of the present embodiment is provided with, for example, an inner middle chamfer 45, a first inner middle sipe 46, and a second inner middle sipe 47.

  The inner middle chamfered portion 45 includes an inclined surface disposed between the tread surface of the inner middle land portion 12 and the side wall on the inner shoulder main groove 4 side.

  The first inner middle sipe 46 is disposed, for example, between the first inner middle lateral groove 43 and the second inner middle lateral groove 44. For example, the first inner middle sipe 46 is inclined in the same direction as the first inner middle lateral groove 43 with respect to the tire axial direction, and completely crosses the inner middle land portion 12.

  For example, the second inner middle sipe 47 extends from the second inner middle lateral groove 44 to the inner shoulder main groove 4. In a desirable mode, the second inner middle sipe 47 is connected to the inner middle chamfer 45. Such a second inner middle sipe 47 can easily deform the land portion in the vicinity of the inner middle chamfered portion 45, and can suppress the clogging of snow in the inner shoulder main groove 4.

  The inner shoulder land portion 9 is provided with, for example, a plurality of inner shoulder lateral grooves 48 and an inner shoulder sipe 49.

  For example, the inner shoulder lateral groove 48 extends from the inner tread end Ti to the inner shoulder main groove 4. In a desirable mode, a region obtained by extending the end portion of the inner shoulder lateral groove 48 along the tire axial direction intersects the first inner middle lateral groove 43 or the inner middle chamfer 45. Thereby, a harder snow column can be formed in the inner shoulder main groove 4.

  The inner shoulder sipe 49 extends, for example, from the inner shoulder main groove 4 to the inner tread end Ti side, and is interrupted before that. For example, the inner shoulder sipe 49 of the present embodiment is preferably inclined in the direction opposite to the first lateral groove 15.

  FIG. 7 is a development view of the tread portion 2 of the tire 1 according to another embodiment of the present invention. In this embodiment, the same code | symbol is attached | subjected to the element which is common in embodiment mentioned above, and description here is abbreviate | omitted.

  In the outer middle land portion 10 of this embodiment, a plurality of penetrating sipes 25 are provided between the first lateral groove 15 and the penetrating groove 19. Such an arrangement of the penetrating sipe 25 helps to further improve the performance on ice.

  The outer shoulder land portion 8 and the inner shoulder land portion 9 are preferably provided with zigzag sipes 50, for example. The zigzag sipe 50 is desirably a semi-open sipe having one end connected to the groove and the other end interrupted in the land. Such a zigzag sipe 50 can suppress a decrease in rigidity of the land portion and maintain steering stability on a dry road surface.

  The outer shoulder land portion 8 and the inner shoulder land portion 9 are preferably provided with a plurality of tread end side sipes 51 extending from the outer tread end To or the inner tread end Ti to the tire equator C side and being interrupted in the land portion. .

  As mentioned above, although the tire of one embodiment of the present invention was explained in detail, the present invention is not limited to the above-mentioned specific embodiment, and can be carried out by changing to various modes.

A pneumatic tire of size 215 / 60R16 having the basic tread pattern of FIG. 1 was prototyped based on the specifications in Table 1. As a comparative example, as shown in FIG. 8, a tire in which a sipe is not connected to the longitudinal groove a in the outer middle land portion was manufactured. The test tires were tested for snow performance and handling stability on dry roads. The common specifications and test methods for each test tire are as follows.
Wearing rim: 16 × 6.5J
Tire internal pressure: 220kPa
Test vehicle: displacement of 2500cc, front-wheel drive vehicle

<Snow performance>
The running performance when running on a snowy road with the test vehicle was evaluated by the driver's sensuality. A result is a score which makes the comparative example 100, and shows that the outstanding performance on snow is continuously exhibited, so that a numerical value is large.

<Operation stability on dry road>
Steering stability when driving on the dry road surface with the test vehicle was evaluated by the driver's sensuality. A result is a score which makes a comparative example 100, and shows that the steering stability on a dry road surface is excellent, so that a numerical value is large.
The test results are shown in Table 1.

  As a result of the test, it was confirmed that the tires of the examples exhibited excellent performance on snow. It was also confirmed that the tires of the examples maintained the steering stability on the dry road surface.

2 Tread portion 10 Land portion 10a First edge 10b Second edge 15 First lateral groove 16 Vertical groove 17 Sipe

Claims (11)

A tire having a tread portion,
The tread portion includes a land portion divided by a first edge extending in the tire circumferential direction and a second edge extending in the tire circumferential direction,
In the land portion, a first transverse groove extending from the first edge toward the second edge and terminating in the land portion,
A longitudinal groove extending in the tire circumferential direction connected to the first lateral groove and having both end portions interrupted in the land portion, and a sipe extending to the second edge side connected to the longitudinal groove;
tire.   The tire according to claim 1, wherein the first lateral groove is inclined with respect to the tire axial direction.   The tire according to claim 1 or 2, wherein the first lateral groove includes a portion having a groove width expanding toward the longitudinal groove side.   The tire according to any one of claims 1 to 3, wherein the vertical groove has a depth smaller than that of the first horizontal groove.   The tire according to any one of claims 1 to 4, wherein the sipe extends to the second edge.   The tire according to any one of claims 1 to 5, wherein the sipe has a depth larger than that of the longitudinal groove.   The tire according to any one of claims 1 to 6, wherein at least a part of the sipe is located in a region in which the first lateral groove is extended in a length direction thereof.   The tire according to any one of claims 1 to 7, wherein the first lateral groove and the sipe are inclined in the same direction with respect to a tire axial direction. The land portion has a chamfered portion including an inclined surface disposed between the tread surface and the side wall on the second edge side,
The tire according to any one of claims 1 to 8, wherein the sipe extends to the chamfered portion. The tread portion includes another land portion adjacent to the land portion via a main groove disposed on the second edge side of the land portion,
The tire according to any one of claims 1 to 9, wherein the other land portion is provided with a second lateral groove continuous with the main groove. The sipe is continuous with the main groove,
The tire according to claim 10, wherein a region obtained by extending the sipe along a length direction thereof intersects with an end portion of the second lateral groove.

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